Freelander 2005 Td4 tool required.

Hi everyone. Having recently queried a Quotation for a clutch kit replacement to my 2005, FL1, Td4, and received fantastic help & advice from LZ members, I have one more question to ask.
To begin with, I have decided to replace the clutch myself, and am now getting my tool-kit together. There is one tool I do not have, and that is the centralising tool for the clutch. I could buy a kit of them, but as I'm only going to use it once - hopefully, might anyone know the diameter of the tool that is inserted? I'm supposing it will match the diameter of the gearbox's shaft.
I once did this on a Rover car & used a broom handle. That worked, so something suitable should also work... I reckon.
Might anyone know?
Thanks.
PS. Using the quotation I received, which was quite staggering, the money saved by doing it DIY will pay for 3 new windows on my Hymer. As well as knowing it will be done to my standards.

I have a universal clutch alignment tool. However if it doesn't fit, I use a socket extension bar and my eye to align the splines centrally in the cover. It's not as difficult as it would appear to be.

As above, socket on extension
If it's not central it will look out.

Not sure if you've seen this or not but half way down you can see my makeshift tool.
Clutch change in a TD4 (list of jobs to do)

Thanks everyone. Geez, it's such a simple remedy too, brilliant. It certainly beats a broom-handle.